1. a person or device that measures the depth of water; one who fathoms
Usage: nautical; technical
2. a person who understands or comprehends something; one who fathoms a mystery or problem
Usage: figurative; informal

Examples

• The ship's fathomer indicated shallow water ahead.
• Modern sonar fathomers have replaced traditional lead lines on most vessels.
• She was a keen fathomer of human nature, always able to read people's intentions.
• The detective proved to be an excellent fathomer of the crime's hidden motives.
• Early sailors relied on simple fathomers to navigate safely through unknown waters.